title: Online version of the food allergy quality of life questionnaire-adult form: validity, feasibility and cross-cultural comparison.
abstract: BACKGROUND
  Food-allergic reactions occur in 3-4% of the adult population in Western countries. It has been shown that food allergy may impair health-related quality of life (HRQL). Food allergy quality of life questionnaires (FAQLQs) have been developed and validated, including an adult form (FAQLQ-AF). These questionnaires may be particularly useful for cross-cultural comparisons.
  
  
  OBJECTIVE
  The aims of this study were to translate the FAQLQ-AF from Dutch into English and validate an online version in the United States. Additionally, HRQL of American and Dutch food-allergic adults was compared.
  
  
  METHODS
  The Dutch FAQLQ-AF was translated into English as set out by the World Health Organization and converted to an electronic online format. Participants (food allergic American adults) were recruited through the 'Food Allergy and Anaphylaxis Network' website and completed the questionnaire online. Construct validity, internal consistency, discriminative ability and feasibility were analysed. A cross-cultural comparison was made using the Dutch FAQLQ-AF scores.
  
  
  RESULTS
  Data from 180 American participants were analysed. The online FAQLQ-AF had a good construct validity (correlation with FAIM: ρ=0.72; P<0.001), internal consistency (Cronbach's α=0.95) and was discriminative for 'anaphylaxis' vs. 'no anaphylaxis' and 'number of food allergies'. The most striking finding was a significantly greater impairment in HRQL in the American participants, as compared with their Dutch counterparts (the total FAQLQ-AF scores were 4.3 vs. 3.5, respectively; P<0.001, where 1 signifies no impairment and 7 signifies extreme impairment in HRQL).
  
  
  CONCLUSIONS
  The online American FAQLQ-AF is a valid instrument to measure HRQL in food-allergic patients in the United States. Additionally, HRQL of American food-allergic adults may be more impaired than Dutch food-allergic adults. The FAQLQ-AF can now be used to determine the HRQL in American food-allergic adults and can assist clinicians in optimizing management strategies for food-allergic patients.
authors.affiliation: Department of Pediatric Pulmonology and Pediatric Allergy, University Medical Centre Groningen, University of Groningen, Groningen, the Netherlands. n.j.goossens@bkk.umcg.nl
authors.forename: N J
authors.initials: NJ
authors.lastname: Goossens
authors.forename: B M J
authors.initials: BM
authors.lastname: Flokstra-de Blok
authors.forename: B J
authors.initials: BJ
authors.lastname: Vlieg-Boerstra
authors.forename: E J
authors.initials: EJ
authors.lastname: Duiverman
authors.forename: C C
authors.initials: CC
authors.lastname: Weiss
authors.forename: T J
authors.initials: TJ
authors.lastname: Furlong
authors.forename: A E J
authors.initials: AE
authors.lastname: Dubois
mesh_terms: D000328:Adult; D003431:Cross-Cultural Comparison; D005240:Feasibility Studies; D005260:Female; D005512:Food Hypersensitivity / Q000523:psychology*; D006801:Humans; D008297:Male; D009426:Netherlands; D009862:Online Systems; D011788:Quality of Life / Q000523:psychology; D011795:Surveys and Questionnaires; D014481:United States